Furnace Hardware

The Fiberfrax® Fiberwall® family of anchoring hardware and accessory components provides an array of attachment options to cover a broad range of lining system designs and application requirements.

Fiberwall® Alloy Stud and Washer Assemblies

Fiberwall alloy stud and washer assemblies are utilized as anchors in layered lining systems.

The studs are available in four standard lengths: 3-1/2”, 4-1/2”, 6”, and 8”. Upon special request, Fiberwall alloy studs are also available in non-standard lengths up to 12” in 1/2” increments. Fiberwall alloy studs and washers are available in four standard alloy grades (304SS, 310SS, 330SS and 601 Inconel). Recommended stud length is determined by adding 1” to the applicable lining thickness.

Fiberwall® Ceramic Cuplocks

When hot face temperatures exceed 1093°C (2000°F) but are below 1149°C (2100°F), the ceramic cuplock retainer can be employed to extend the recommended operating temperature of the 601 Inconel stud to 1149°C (2100°F). The alloy washer is not required when the cuplock is used to retain the insulation lining.

The stud length dimension, when using a 2” cuplock retainer, is determined by subtracting 1” from the applicable lining thickness. To be effective, the cuplock’s inner core must be filled with LDS moldable. This can be done either before or after engaging the cuplock to the stud’s tip. The 1” cuplock is used primarily in layered lining over refractory (L.O.R.) installations where lining thickness is usually 2” or less, corrosive elements are present in the fuel, or when the hot face temperature is below 1121°C (2050°F). Typically, the 1” cuplock is used in conjunction with barbed 601 Inconel studs in L.O.R. Applications. The “barb” of a barbed stud is configured so that it will easily enter within, but will lock securely to, predrilled holes in the refractory surface. LDS Moldable® is employed as a filler to plug the cuplock’s 1” deep core and, as in the 2” cuplock, is carried over to the face of the cuplock to effectively seal around the core’s perimeter edge.

Fiberwall® Ceramic Bearing Ring

The ceramic bearing ring is used in higher temperature layered lining applications, particularly on roofs, where added bearing support may be required. The bearing ring is used in conjunction with a cuplock, or ceramic washer. The maximum recommended operating temperature should be limited to 1343°C (2450°F).

Fiberwall® Ceramic Whistle Stud Assembly

The ceramic whistle stud assembly is comprised of three distinct components:

  • The adjustable whistle (or base)
  • The high-alumina spike
  • The ceramic washer

The adjustable whistle base is a two-component, adjustable length system consisting of a whistle base (with retaining pin) and a 1/4” -20 NC x 1-1/4” long arc welded stud. After the stud is arc stud welded to the casing plate, the whistle base is screwed onto the stud. This feature provides up to 1/2” adjustment of the overall assembly length.

The second component of the ceramic whistle stud assembly is the high-alumina ceramic spike which is available in seven standard lengths.

The third component, the ceramic washer, is available in two ceramic compositions: high-alumina and mullite. Like the spike, the high-alumina washer’s recommended operating temperature extends to 1510°C (2750°F). The mullite ceramic washer’s minimum recommended operating temperature, while only 1343°C (2450°F), affords excellent resistance to thermal shock.

Fiberwall® Stackstuds

Stackstud type anchors are required in the construction of stackbond lining systems. Stackbond linings consist of layers of blanket strips, or folded blanket battens, that are stacked together and simultaneously impaled and compressed over the stackstud anchor. Both blanket strips and folded blanket battens are compressed about 25% when installed. Stackstuds are available in standard alloy grades 304SS and 310SS. 601 Inconel is available by special request.

Hefty-Loc Anchor Assembly

The Hefty-Loc anchor assembly is a multipurpose, two component anchor consisting of a tine and base leg. Hefty-Loc anchors can be utilized as stackstuds in the construction of stackbond lining systems or in the construction of Fiberwall Hefty-Loc bonded modular lining systems.

Tines are available in half or full-length beams. Base leg options allow for hand welding or for arc stud gun welding to the casing plate. Hefty-Loc anchor assemblies are available in standard alloy grades of 304 SS and 310 SS. 601 Inconel is available by special request.


Refer to the product Safety Data Sheet (SDS) for recommended work practices and other product safety information.

For additional information on products, properties and performance, typical applications, or to identify the recommended product for your application, see the product information sheet listed above or contact the Unifrax Application Engineering Department at 716-768-6460.